1. Field of the Invention
This invention relates to a lighting device, and more particularly, to an ornamental lighting device with a flexibly-shapable light emitting tube that can be bent into user-designed signs, such as marks, graphics, letters, and many various others, and portray these signs in a flickering manner.
2. Description of Related Art
FIG. 1 is a schematic perspective diagram of a conventional ornamental lighting device with a part cut away to show the inside structure. As shown, this conventional ornamental lighting device includes an elongated transparent tube which is made from PVC that allows it to be bent into any shape. The elongated transparent tube is formed with two longitudinally-extending grooves 2 for mounting two respective bands of serially-connected lamps 3 therein. These lamps 3 are connected to electrical contacts 1 mounted on the external side of the elongated transparent tube. The elongated transparent tube is wrapped in PVC insulation 4 which is typically colored to allow the lights emitted from the lamps 3 to display certain colors that are prescribed by the art designer. A controller (not shown) is connected via the electrical contacts 1 to these lamps 3, which can control the on/off states of the lamps 3 in any predetermined sequences.
One drawback to the foregoing ornamental lighting device, however, is that the number of lamps mountable in the grooves 2 is limited. The number of patterns that can express chasing light produced by the ornamental lighting device is therefore limited. Moreover, since the mounting of the two bands of lamps 3 in the elongated transparent tube requires the forming of two grooves 2 in the elongated transparent tube, the overall size of the ornamental lighting device is considerably bulky, making the ornamental lighting device less compact in size. If it is desired to increase the number of flickering patterns that can express chasing light produced by the ornamental lighting device, the wires interconnecting the lamps 3 the grooves 2 for mounting the lamps 3 should be both increased in number, which will make the overall size of the ornamental lighting device even more bulky and require more even components to assemble. The manufacture of the ornamental lighting device is also difficult to carry out and also high in cost. Moreover, since the lamps 3 of the ornamental lighting device of FIG. 1 are necessarily arranged on opposite sides of the elongated transparent tube, the lights emitted therefrom are scattered rather than concentrated, resulting in an uneven flickering effect.
Another conventional ornamental lighting device is shown in FIGS. 2 through 4. As shown in FIGS. 2 and 3, this ornamental lighting device also includes an elongated transparent tube 5 wrapped in PVC insulation 4. The elongated transparent tube 5 has a hollowed inside in which a single band of serially-connected lamps 3 is mounted. The lamps 3 are interconnected by insulated copper wires 7 and connected to a plurality of electrical contacts 1, 1a, 1b, 1c provided on the outside of the elongated transparent tube 5, of which the electrical contact 1 is connected to a common wire. Moreover, as shown in FIG. 2, the PVC insulation 4 is formed with a V-shaped opening 6. In assembly, this V-shaped opening 6 allows the lamps 3 to be mounted in the hollowed inside of the elongated transparent tube 5 by inserting them through this V-shaped opening 6.
One drawback to the foregoing ornamental lighting device, however, is that the interconnecting wires 7 for the lamps 3 in the elongated transparent tube 5 should not be too large in number; otherwise, they can obstruct the light emitted from the lamps 3 or cause short-circuits with each other. Therefore, as shown in FIG. 4, the lamps 3 can only be interconnected in a fixed manner, and cannot be arranged arbitrarily by the art designer for more creative patterns.